Quick Bash Wins
Don’t waste tokens asking “can you run git status?” or “can you check the tests?”
Just type: ! followed by your bash command.
The ! prefix executes bash instantly and injects the output into context. No model processing. No delay. No wasted tokens.
What the ! Prefix Does
The ! prefix (also called Bash Mode) runs commands directly in Claude Code’s persistent shell session, bypassing Claude’s AI entirely.
Two ways to use it:
- In the chat: Type
!followed by any bash command - In custom slash commands: Embed
!commands to inject dynamic context
When you use !, the command executes immediately in the shell, and the output appears as context—but Claude never processes the command itself. You skip the AI roundtrip entirely.
Direct Command Examples
Instead of asking Claude to run commands, just run them:
! git status
! npm test
! ls -la
! git branch --show-current
! df -hThe output appears instantly, and you can reference it in your next prompt. No “Claude, can you…” overhead. No tokens wasted on conversational back-and-forth.
In Custom Slash Commands
The real power shows up in custom slash commands. You can embed bash execution that runs before the slash command processes:
---
name: commit
description: Create a git commit with context
allowed-tools: Bash(git status:*), Bash(git diff:*)
---
## Current State
- Status: !`git status`
- Staged changes: !`git diff --staged`
- Branch: !`git branch --show-current`
[Rest of your slash command prompt...]The ! commands execute first. Their output becomes part of the command context. Claude sees the live state of your repository without needing to ask for it.
This enables dynamic, context-aware slash commands that adapt to your project’s current state.
When to Use It
Use ! anytime you need command output but not AI interpretation:
- Status checks:
! git status,! git log -1 - Directory exploration:
! ls -la,! tree -L 2 - Test runs:
! npm test,! pytest - Build verification:
! npm run build,! cargo check - System info:
! uptime,! df -h
If you just want the output injected as context, use !. If you need Claude to analyze or act on the output, use the Bash tool normally.
Why This Matters
Token efficiency: Every time you ask Claude “can you run X command?”, you’re burning tokens on conversation. The ! prefix skips that entirely.
Speed: Instant execution. No waiting for Claude to process your request, call the Bash tool, and format a response.
Context clarity: The output appears exactly as the shell produces it. No conversational wrapper. No “Here’s what I found…” preamble.
For developers using Claude Code regularly, the ! prefix is one of those small features that compounds into significant efficiency gains. Faster workflows, lower token usage, cleaner context.
Try it yourself: Next time you need git status, don’t ask. Just type ! git status.
Credit: This tip was highlighted by @adocomplete from Anthropic as part of his Advent of Claude series.
Resources: